Gold-catalyzed synthesis of oxazoles from alkynyl triazenes and dioxazoles

Abstract

A gold-catalyzed regioselective [3 + 2] cycloaddition of alkynyl triazenes with 1,2,4-dioxazoles was developed.

Activation of metal-involved halogen bonds and classical halogen bonds in gold(i) catalysis

“…In this work, the cyclization reaction of propargylic amides 28–31 was investigated using Ph 3 PAuCl as a catalyst and halogen bond donors (C 4 H 2 INO 2 , C 6 F 5 I, C 8 H 9 O 2 I) as activators. We mainly focused on the following points: (1) designing and assessing two activation modes in gold( i ) catalysis: the halogen bond donor activates the Cl atom of Ph 3 PAuCl to form X–I⋯Cl (X = C, N) classical halogen bonding and activates the Au atom of Ph 3 PAuCl to form X–I⋯Au (X = C, N) metal-involved halogen bonding; (2) investigating the reaction mechanism of the cyclization reaction of propargylic amides by using halogen bond activation to gold( i ) catalysts; (3) comparing the activation ability of metal-involved halogen bonding and classical halogen bonding for gold( i ) catalysts.…”